<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
    <style>
        .blue{
            width: 500px;
            height: 500px;
            background-color:rgb(26, 26, 237);
            margin-left:200px;
            margin-top:100px;
        }
        .pink{
            width:120px;
            height:120px;
            background-color: pink;
            position: relative;
            top:100px;
            left:20px;

        }
    </style>
<body>
    <div class="blue">
        <div class="pink"></div>
        <div class="yellow"></div>
        <div class="green"></div>
    </div>
</body>
</html>